NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy leve...NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.展开更多
Although ionic liquids(ILs)have been widely employed to heal the defects in perovskite solar cells(PSCs),the corresponding defect passivation mechanisms are not thoroughly understood up to now.Herein,we first reveal a...Although ionic liquids(ILs)have been widely employed to heal the defects in perovskite solar cells(PSCs),the corresponding defect passivation mechanisms are not thoroughly understood up to now.Herein,we first reveal an abnormal buried interface anion defect passivation mechanism depending on cationinduced steric hindrance.The IL molecules containing the same anion([BF4]^(-))and different sizes of imidazolium cations induced by substituent size are used to manipulate buried interface.It was revealed what passivated interfacial defects is mainly anions instead of cations.Theoretical and experimental results demonstrate that the large-sized cations can weaken the ionic bond strength between anions and cations,and facilitate the interaction between anions and SnO2as well as perovskites,which is conducive to interfacial defect passivation and ameliorating interfacial contact.It can be concluded that interfacial chemical interaction strength and defect passivation effect are positively correlated with the size of cations.The discovery breaks conventional thinking that large-sized modification molecules would weaken their chemical interaction with perovskite.Compared with the control device(21.54%),the device based on 1,3-Bis(1-adamantyl)-imidazolium tetrafluoroborate(BAIMBF4)with maximum size cations achieves a significantly enhanced efficiency of 23.61%along with much increased moisture,thermal and light stabilities.展开更多
The rapid development of low-bandgap(LBG)nonfullerene acceptors and wide-bandgap(WBG)copolymer donors in recent years has boosted the power conversion efficiency(PCE)of organic solar cells(OSCs)to the 18%level[1−21].T...The rapid development of low-bandgap(LBG)nonfullerene acceptors and wide-bandgap(WBG)copolymer donors in recent years has boosted the power conversion efficiency(PCE)of organic solar cells(OSCs)to the 18%level[1−21].The commercialization of OSCs is highly expected.However,critical issues like the cost and the stability also determine whether OSCs can enter the market or not[22].展开更多
Organic–inorganic hybrid perovskite materials demonstrate promising applications in high-efficiency perovskite solar cells (PSCs) with a certified power conversion efficiency(PCE) of 25.5%(https://www.nrel.gov/pv/cel...Organic–inorganic hybrid perovskite materials demonstrate promising applications in high-efficiency perovskite solar cells (PSCs) with a certified power conversion efficiency(PCE) of 25.5%(https://www.nrel.gov/pv/cell-efficiency.html).展开更多
Organic-inorganic hybrid perovskite solar cell(PSC)is a third-generation photovoltaic technology^([1,2]),and the certi-fied power conversion efficiency(PCE)has reached 25.5%(https://www.nrel.gov/pv/cell-efficiency.htm...Organic-inorganic hybrid perovskite solar cell(PSC)is a third-generation photovoltaic technology^([1,2]),and the certi-fied power conversion efficiency(PCE)has reached 25.5%(https://www.nrel.gov/pv/cell-efficiency.html),which can rival solar cells based on crystalline-Si and other inorganic semi-conductors.The intrinsic instability of perovskite materials could impede PSC commercialization^([3]).To date,a variety of strategies such as composition engineering,additive engi-neering,interface engineering and encapsulation technique are employed to improve the long-term stability of PSCs^([4−9]).展开更多
Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an ab...Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an abundant component.Vanadium is an essential tool to determine the relationship of the Earth with extra-terrestrial bodies.In the Yangtze region,the black rocks of the Early Cambrian Niutitang Formation are highly enriched in the concentration of V,Co,Ni and Mo.These sediments are comprised of a high total organic carbon content,and the average concentration of vanadium is over 240 ppm.Here we discuss the mechanisms and conditions that were responsible for the accumulation of vanadium in these black sediments in the Yangtze region.The oxygenated ocean water is favorable for the dissolved vanadate species Ⅴ(Ⅴ).Therefore,in oxic ocean-water,it can be reduced by organic matters or by H_(2)S to vanadyl ions Ⅴ(Ⅳ),which can facilely be adsorbed to the tiny particles and finally deposit into the sediments with the settling of the particles.The presence of V_(2)O_(3) in the Niutitang Formation indicates the isomorphism state of vanadium existence in the clay minerals.Clays and pyrite are the most favorable mineral for vanadium enrichment.However,it is suggested the quartz of non-biogenic origin might be unfavorable for vanadium enrichment.Vanadium is mainly derived from the diagenetic transformation of its precursor(porphyrin pigments and chlorophyll)from the organism.During the Early Cambrian period,the massive transgression in the sea level created a favorable environment for organisms to survive.Additionally,the hydrothermal activities brought massive nutrient supply in the form of vanadium and other metal elements from the deep Earth.These creatures consumed the vanadium-rich nutrients,which became a part of their bodies in the form of hard and soft parts.Later on,when these organisms died and were submerged in the sediments.After the diagenetic actions,this vanadium became a part of these black sediments along with organic carbon.Therefore,these black rocks in the Yangtze region are enriched in vanadium and organic carbon.It is suggested the various processes such as adsorption,complexation,and reductions are the main factors responsible for the precipitation of dissolved vanadium into the organically rich sediments.展开更多
This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,a...This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.展开更多
Two-dimensional(2D)/quasi-2D perovskite solar cells(PSCs)incorporating organic spacer cations exhibit appealing ambient stability in comparison with their 3D analogs.Most reported organic spacer cations are based on a...Two-dimensional(2D)/quasi-2D perovskite solar cells(PSCs)incorporating organic spacer cations exhibit appealing ambient stability in comparison with their 3D analogs.Most reported organic spacer cations are based on ammonium,whereas formamidinium(FA^(+))has been seldom applied despite that FA has been extensively used in high-efficiency 3D PSCs.Herein,a novel FA-based organic spacer cation,4-chloro-phenylformamidinium(CPFA^(+)),is applied in quasi-2D Ruddlesden-Popper(RP)PSCs for the first time,and methylammonium chloride(MACl)is employed to promote crystal growth and orientation of perovskite film,resulting in high power conversion efficiency(PCE)with improved stability.Upon incorporating CPFA+organic spacer cation and MACl additive,high-quality quasi-2D CPFA_(2)MA_(n-1)Pb_(n)(I_(0.857)Cl_(0.143))_(3n+1)(n=9)perovskite film forms,exhibiting improved crystal orientation,reduced trap state density,prolonged carrier lifetime and optimized energy level alignment.Consequently,the CPFA_(2)MA_(n-1)Pb_(n)(I_(0.857)Cl_(0.143))_(3n+1)(n=9)quasi-2D RP PSC devices deliver a highest PCE of 14.78%.Moreover,the un-encapsulated CPFA-based quasi-2D RP PSC devices maintain~80%of its original PCE after exceeding 2000 h storage under ambient condition,whereas the 3D MAPb I3counterparts retain only~45%of its original PCE.Thus,the ambient stability of quasi-2D RP PSC devices is improved obviously relative to its 3D MAPb I3counterpart.展开更多
The interfaces between electrodes/photoactivelayer play a determinative role on the performanceof polymer solar cells(PSCs),improving the con-tact between electrodes and photoactive layer via in-terface engineering ha...The interfaces between electrodes/photoactivelayer play a determinative role on the performanceof polymer solar cells(PSCs),improving the con-tact between electrodes and photoactive layer via in-terface engineering has been demonstrated to an ef-fective solution to enhance the performance of PSCs.Graphenes have been generally applied as hole ex-traction layer in PSCs to replace the commonly展开更多
Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compou...Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compound has never been reported.Herein,by encapsulating a ternary transition metallanthanide heteronuclear dimetallic nitride into a C_(84) fullerene cage,transition metal−nitrogen and lanthanide-nitrogen double bonds are costabilized simultaneously within the as-formed clusterfullerene TiCeN@C_(1)(12)-C_(84),which is a representative heteronuclear dimetallic nitride clusterfullerene.Its molecular structure was unambiguously determined by single-crystal X-ray diffraction,revealing a slightly bentμ2-bridged nitride cluster with short Ti−N(1.761Å)and Ce−N(2.109Å)bond lengths,which are comparable to the corresponding Ti=N and Ce=N double bonds of reported metal complexes and consistent with the theoretically predicted values,confirming their coexistence within TiCeN@C_(1)(12)-C_(84).Density functional theory(DFT)calculations unveil three-center two-electron(3c-2e)bonds delocalized over the entire TiCeN cluster,which are responsible for costabilization of Ti�N and Ce�N double bonds.An electronic configuration of Ti4+Ce^(3+)N^(3−)@C_(84)^(4−)is proposed featuring an intramolecular four-electron transfer,drastically different from the analogous actinide dimetallic nitride clusterfullerene(U_(2))^(9+)N^(3−)@C_(80)^(6−)and trimetallic nitride clusterfullerene(Sc_(2))^(6+)Ti^(3+)^(N3−)@C_(80)^(6−),indicating the peculiarity of 4-fold negatively charged fullerene cage in stabilizing the heteronuclear dimetallic nitride cluster.展开更多
Comprehensive Summary,Efficient charge transport and defect passivation are essential for high efficiency of organic–inorganic hybrid perovskite solar cells(PSCs).Functionalized fullerenes featuring high electron aff...Comprehensive Summary,Efficient charge transport and defect passivation are essential for high efficiency of organic–inorganic hybrid perovskite solar cells(PSCs).Functionalized fullerenes featuring high electron affinity and mobility as well as small reorganization energy have been extensively applied in PSCs toward facilitated electron transport and passivated trap states,leading to improvements of both device efficiency and stability.Herein,we summarize the recent advances,especially in the last three years,in applications of functionalized fullerenes including fullerene derivatives and endohedral metallofullerenes in PSCs.Their functions in trap state passivation,electron transport promotion,crystalline modulation,water/oxygen erosion inhibition,and so on,are discussed in details.In particular,we emphasize novel functions of fullerenes beyond trap state passivation,as well as the synergy of multifunction of fullerenes in improving PSC device performance and stability.Finally,we present an outlook on designing novel multifunctionalized fullerenes toward highly efficient and stable PSC devices.展开更多
In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing th...In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing their efficiency.Herein,chemically stable tungsten trioxide(WO3)with high electron mobility is used as electron transport material in methylamine(MA)-free PSCs.However,the light-soaking effect is observed apparently in our devices.A fullerene derivative,C60 pyrrolidine Tris-acid(CPTA),is introduced to modify the interface between WO3 and perovskite(PVK)layers,which can bond with WO3 and PVK simultaneously,leading to the passivation of the defect and the suppression of trap-assisted nonradiative recombination.What is more,the introduction of CPTA can enhance the built-in electric field between WO3 and PVK layers,thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface.Consequently,the lightsoaking effect of WO3-based PSCs has been eliminated,and the power conversion efficiency has been boosted from 17.4%for control device to 20.5%for WO3/CPTA-based PSC with enhanced stability.This study gives guidance for the design of interfacial molecules to eliminate the light-soaking effect.展开更多
All-inorganic CsPbI_(3-x)Br_(x)perovskite solar cells(PSCs)are advantageous in terms of high thermal stability,while its efficiency lags behind those of organic-inorganic hybrid perovskite counterparts.Defect passivat...All-inorganic CsPbI_(3-x)Br_(x)perovskite solar cells(PSCs)are advantageous in terms of high thermal stability,while its efficiency lags behind those of organic-inorganic hybrid perovskite counterparts.Defect passivations have been extensively applied for enhancing efficiency of all-inorganic PSCs,which are mainly based on univocal defect passivation of perovskite layer.Herein,we incorporated a bis-dimethylamino-functionalized fullerene derivative(abbreviated as PCBDMAM)as an interlayer between ZnO electron transport layer(ETL)and all-inorganic CsPbI_(2.25)Br_(0.75)perovskite layer,accomplishing synchronous defect passivations of both layers and consequently dramatic enhancements of efficiency and thermal stability of PSC devices.Upon spin-coating PCBDMAM onto ZnO ETL,the surface defects of ZnO especially oxygen vacancies can be effectively passivated due to the formation of Zn−N ionic bonds.In addition,PCBDMAM incorporation affords effective passivation of Pb_(I)and I_(Pb)antisite defects within the atop perovskite layer as well via coordination bonding with Pb^(2+).As a result,the regular-structure planar CsPbI_(2.25)Br_(0.75)PSC device delivers a champion power conversion efficiency(PCE)of 17.04%,which surpasses that of the control device(15.44%).Moreover,the PCBDMAM-incorporated PSC device maintains~80%of its initial PCE after 600 h heating at 85°C hot plate in N2 atmosphere,whereas PCE of the control device degrades rapidly to~62%after 460 h heating under identical conditions.Hence,PCBDMAM incorporation benefited dramatic improvement of the thermal stability of PSC device.展开更多
In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic...In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,17%power conversion efficiencies(PCEs)have been achieved in the state-of-the-art OSCs[2,3].The remarkable progress in OSCs relies on the continuously emerging new materials and device fabrication technologies,and the understanding on film morphology and device physics[4,5].展开更多
Nowadays,wide-bandgap(WBG)copolymers attract great attention in the field of organic photovoltaics[1].They are ideal electron-donating partners for low-bandgap small molecule acceptors[2-12].With good energy levels ma...Nowadays,wide-bandgap(WBG)copolymers attract great attention in the field of organic photovoltaics[1].They are ideal electron-donating partners for low-bandgap small molecule acceptors[2-12].With good energy levels matching,the blend of WBG copolymer donor and small molecule acceptor can harvest most of the sunlight and deliver high power conversion efficiencies(PCEs)in solar cells.PCEs higher than 16%have been achieved[13-15].WBG copolymers especially those with ultra-wide bandgaps(i.e.,optical bandgap(Eg opt)>2.07 eV,absorption onset<600 nm)can find applications in ternary solar cells[16]and tandem solar cells[17].Currently,ultra-WBG copolymer donors are less efficient,generally giving PCEs below 13%[18].Designing highly efficient ultra-WBG copolymers is needed.In this work,we use fluorine-and alkoxyl-substituted benzene(FAB)as the building block to construct ultra-WBG copolymer donors.展开更多
Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs...Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs)over 13% have been realized in single-junction NFOSCs[2].Compared with traditional fullerene acceptors,the greatest advantage of nonfullerene acceptors is their stronger light-harvesting capability in the visible and展开更多
Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://...Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell-efficiency.html.展开更多
Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,18%power conversion efficiency has been achieved in the sta...Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,18%power conversion efficiency has been achieved in the state-of-the-art organic solar cells.The recent rapid progress in organic solar cells relies on the continuously emerging new materials and device fabrication technologies,and the deep understanding on film morphology,molecular packing and device physics.Donor and acceptor materials are the key materials for organic solar cells since they determine the device performance.The past 25 years have witnessed an odyssey in developing high-performance donors and acceptors.In this review,we focus on those star materials and milestone work,and introduce the molecular structure evolution of key materials.These key materials include homopolymer donors,D-A copolymer donors,A-D-A small molecular donors,fullerene acceptors and nonfullerene acceptors.At last,we outlook the challenges and very important directions in key materials development.展开更多
文摘NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.
基金financially supported by the Support Plan for Overseas Students to Return to China for Entrepreneurship and Innovation(cx2020003)the Fundamental Research Funds for the Central Universities(2020CDJ-LHZZ-074 and 2021CDJQY-022)Natural Science Foundation of Chongqing(cstc2020jcyjmsxmX0629)。
文摘Although ionic liquids(ILs)have been widely employed to heal the defects in perovskite solar cells(PSCs),the corresponding defect passivation mechanisms are not thoroughly understood up to now.Herein,we first reveal an abnormal buried interface anion defect passivation mechanism depending on cationinduced steric hindrance.The IL molecules containing the same anion([BF4]^(-))and different sizes of imidazolium cations induced by substituent size are used to manipulate buried interface.It was revealed what passivated interfacial defects is mainly anions instead of cations.Theoretical and experimental results demonstrate that the large-sized cations can weaken the ionic bond strength between anions and cations,and facilitate the interaction between anions and SnO2as well as perovskites,which is conducive to interfacial defect passivation and ameliorating interfacial contact.It can be concluded that interfacial chemical interaction strength and defect passivation effect are positively correlated with the size of cations.The discovery breaks conventional thinking that large-sized modification molecules would weaken their chemical interaction with perovskite.Compared with the control device(21.54%),the device based on 1,3-Bis(1-adamantyl)-imidazolium tetrafluoroborate(BAIMBF4)with maximum size cations achieves a significantly enhanced efficiency of 23.61%along with much increased moisture,thermal and light stabilities.
基金We thank the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720,62074022)+1 种基金Fundamental Research Funds for the Central Universities(2020CDJQY-A055)the Youth Association for Promoting Innovation(CAS)for financial support.
文摘The rapid development of low-bandgap(LBG)nonfullerene acceptors and wide-bandgap(WBG)copolymer donors in recent years has boosted the power conversion efficiency(PCE)of organic solar cells(OSCs)to the 18%level[1−21].The commercialization of OSCs is highly expected.However,critical issues like the cost and the stability also determine whether OSCs can enter the market or not[22].
基金supported by the National Key Research and Development Program of China (2017YFA0402800)National Natural Science Foundation of China (51925206,U1932214)+2 种基金Collaborative Innovation Program of Hefei Science Center (2020HSC-CIP004)the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China (51773045, 21772030, 51922032, 21961160720)for financial support。
文摘Organic–inorganic hybrid perovskite materials demonstrate promising applications in high-efficiency perovskite solar cells (PSCs) with a certified power conversion efficiency(PCE) of 25.5%(https://www.nrel.gov/pv/cell-efficiency.html).
基金supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(51925206,U1932214)+1 种基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)for financial support.
文摘Organic-inorganic hybrid perovskite solar cell(PSC)is a third-generation photovoltaic technology^([1,2]),and the certi-fied power conversion efficiency(PCE)has reached 25.5%(https://www.nrel.gov/pv/cell-efficiency.html),which can rival solar cells based on crystalline-Si and other inorganic semi-conductors.The intrinsic instability of perovskite materials could impede PSC commercialization^([3]).To date,a variety of strategies such as composition engineering,additive engi-neering,interface engineering and encapsulation technique are employed to improve the long-term stability of PSCs^([4−9]).
基金the National Natural Science Foundation(NNCF)of China for awarding us pecuniary aid with Grant Numbers 41572099,and 41872127 to accomplish this scientific research.
文摘Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an abundant component.Vanadium is an essential tool to determine the relationship of the Earth with extra-terrestrial bodies.In the Yangtze region,the black rocks of the Early Cambrian Niutitang Formation are highly enriched in the concentration of V,Co,Ni and Mo.These sediments are comprised of a high total organic carbon content,and the average concentration of vanadium is over 240 ppm.Here we discuss the mechanisms and conditions that were responsible for the accumulation of vanadium in these black sediments in the Yangtze region.The oxygenated ocean water is favorable for the dissolved vanadate species Ⅴ(Ⅴ).Therefore,in oxic ocean-water,it can be reduced by organic matters or by H_(2)S to vanadyl ions Ⅴ(Ⅳ),which can facilely be adsorbed to the tiny particles and finally deposit into the sediments with the settling of the particles.The presence of V_(2)O_(3) in the Niutitang Formation indicates the isomorphism state of vanadium existence in the clay minerals.Clays and pyrite are the most favorable mineral for vanadium enrichment.However,it is suggested the quartz of non-biogenic origin might be unfavorable for vanadium enrichment.Vanadium is mainly derived from the diagenetic transformation of its precursor(porphyrin pigments and chlorophyll)from the organism.During the Early Cambrian period,the massive transgression in the sea level created a favorable environment for organisms to survive.Additionally,the hydrothermal activities brought massive nutrient supply in the form of vanadium and other metal elements from the deep Earth.These creatures consumed the vanadium-rich nutrients,which became a part of their bodies in the form of hard and soft parts.Later on,when these organisms died and were submerged in the sediments.After the diagenetic actions,this vanadium became a part of these black sediments along with organic carbon.Therefore,these black rocks in the Yangtze region are enriched in vanadium and organic carbon.It is suggested the various processes such as adsorption,complexation,and reductions are the main factors responsible for the precipitation of dissolved vanadium into the organically rich sediments.
文摘This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.
基金supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(51925206,U1932214)。
文摘Two-dimensional(2D)/quasi-2D perovskite solar cells(PSCs)incorporating organic spacer cations exhibit appealing ambient stability in comparison with their 3D analogs.Most reported organic spacer cations are based on ammonium,whereas formamidinium(FA^(+))has been seldom applied despite that FA has been extensively used in high-efficiency 3D PSCs.Herein,a novel FA-based organic spacer cation,4-chloro-phenylformamidinium(CPFA^(+)),is applied in quasi-2D Ruddlesden-Popper(RP)PSCs for the first time,and methylammonium chloride(MACl)is employed to promote crystal growth and orientation of perovskite film,resulting in high power conversion efficiency(PCE)with improved stability.Upon incorporating CPFA+organic spacer cation and MACl additive,high-quality quasi-2D CPFA_(2)MA_(n-1)Pb_(n)(I_(0.857)Cl_(0.143))_(3n+1)(n=9)perovskite film forms,exhibiting improved crystal orientation,reduced trap state density,prolonged carrier lifetime and optimized energy level alignment.Consequently,the CPFA_(2)MA_(n-1)Pb_(n)(I_(0.857)Cl_(0.143))_(3n+1)(n=9)quasi-2D RP PSC devices deliver a highest PCE of 14.78%.Moreover,the un-encapsulated CPFA-based quasi-2D RP PSC devices maintain~80%of its original PCE after exceeding 2000 h storage under ambient condition,whereas the 3D MAPb I3counterparts retain only~45%of its original PCE.Thus,the ambient stability of quasi-2D RP PSC devices is improved obviously relative to its 3D MAPb I3counterpart.
文摘The interfaces between electrodes/photoactivelayer play a determinative role on the performanceof polymer solar cells(PSCs),improving the con-tact between electrodes and photoactive layer via in-terface engineering has been demonstrated to an ef-fective solution to enhance the performance of PSCs.Graphenes have been generally applied as hole ex-traction layer in PSCs to replace the commonly
基金National Natural Science Foundation of China(51925206,U1932214,52302052,22301288)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)+2 种基金Anhui Provincial Natural Science Foundation(2308085MB33,2308085MB31)Fundamental Research Funds for the Central Universities(20720220009,WK2060000051)National Synchrotron Radiation Laboratory(KY2060000240).
文摘Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compound has never been reported.Herein,by encapsulating a ternary transition metallanthanide heteronuclear dimetallic nitride into a C_(84) fullerene cage,transition metal−nitrogen and lanthanide-nitrogen double bonds are costabilized simultaneously within the as-formed clusterfullerene TiCeN@C_(1)(12)-C_(84),which is a representative heteronuclear dimetallic nitride clusterfullerene.Its molecular structure was unambiguously determined by single-crystal X-ray diffraction,revealing a slightly bentμ2-bridged nitride cluster with short Ti−N(1.761Å)and Ce−N(2.109Å)bond lengths,which are comparable to the corresponding Ti=N and Ce=N double bonds of reported metal complexes and consistent with the theoretically predicted values,confirming their coexistence within TiCeN@C_(1)(12)-C_(84).Density functional theory(DFT)calculations unveil three-center two-electron(3c-2e)bonds delocalized over the entire TiCeN cluster,which are responsible for costabilization of Ti�N and Ce�N double bonds.An electronic configuration of Ti4+Ce^(3+)N^(3−)@C_(84)^(4−)is proposed featuring an intramolecular four-electron transfer,drastically different from the analogous actinide dimetallic nitride clusterfullerene(U_(2))^(9+)N^(3−)@C_(80)^(6−)and trimetallic nitride clusterfullerene(Sc_(2))^(6+)Ti^(3+)^(N3−)@C_(80)^(6−),indicating the peculiarity of 4-fold negatively charged fullerene cage in stabilizing the heteronuclear dimetallic nitride cluster.
基金supported by the National Natural Science Foundation of China(52172053,51925206,U1932214)the Guangdong Basic and Applied Basic Research Foundation(2022A1515140089).
文摘Comprehensive Summary,Efficient charge transport and defect passivation are essential for high efficiency of organic–inorganic hybrid perovskite solar cells(PSCs).Functionalized fullerenes featuring high electron affinity and mobility as well as small reorganization energy have been extensively applied in PSCs toward facilitated electron transport and passivated trap states,leading to improvements of both device efficiency and stability.Herein,we summarize the recent advances,especially in the last three years,in applications of functionalized fullerenes including fullerene derivatives and endohedral metallofullerenes in PSCs.Their functions in trap state passivation,electron transport promotion,crystalline modulation,water/oxygen erosion inhibition,and so on,are discussed in details.In particular,we emphasize novel functions of fullerenes beyond trap state passivation,as well as the synergy of multifunction of fullerenes in improving PSC device performance and stability.Finally,we present an outlook on designing novel multifunctionalized fullerenes toward highly efficient and stable PSC devices.
基金National Natural Science Foundation of China,Grant/Award Numbers:51925206,U1932214National Key Research and Development Program of China,Grant/Award Number:2017YFA0402800。
文摘In perovskite solar cells(PSCs),the light-soaking effect,which means device performance changes obviously under continuous light illumination,is potentially harmful to loaded devices as well as accurately assessing their efficiency.Herein,chemically stable tungsten trioxide(WO3)with high electron mobility is used as electron transport material in methylamine(MA)-free PSCs.However,the light-soaking effect is observed apparently in our devices.A fullerene derivative,C60 pyrrolidine Tris-acid(CPTA),is introduced to modify the interface between WO3 and perovskite(PVK)layers,which can bond with WO3 and PVK simultaneously,leading to the passivation of the defect and the suppression of trap-assisted nonradiative recombination.What is more,the introduction of CPTA can enhance the built-in electric field between WO3 and PVK layers,thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface.Consequently,the lightsoaking effect of WO3-based PSCs has been eliminated,and the power conversion efficiency has been boosted from 17.4%for control device to 20.5%for WO3/CPTA-based PSC with enhanced stability.This study gives guidance for the design of interfacial molecules to eliminate the light-soaking effect.
基金This work was partially supported by the National Natural Science Foundation of China(Nos.51925206,U1932214,and 52172053)。
文摘All-inorganic CsPbI_(3-x)Br_(x)perovskite solar cells(PSCs)are advantageous in terms of high thermal stability,while its efficiency lags behind those of organic-inorganic hybrid perovskite counterparts.Defect passivations have been extensively applied for enhancing efficiency of all-inorganic PSCs,which are mainly based on univocal defect passivation of perovskite layer.Herein,we incorporated a bis-dimethylamino-functionalized fullerene derivative(abbreviated as PCBDMAM)as an interlayer between ZnO electron transport layer(ETL)and all-inorganic CsPbI_(2.25)Br_(0.75)perovskite layer,accomplishing synchronous defect passivations of both layers and consequently dramatic enhancements of efficiency and thermal stability of PSC devices.Upon spin-coating PCBDMAM onto ZnO ETL,the surface defects of ZnO especially oxygen vacancies can be effectively passivated due to the formation of Zn−N ionic bonds.In addition,PCBDMAM incorporation affords effective passivation of Pb_(I)and I_(Pb)antisite defects within the atop perovskite layer as well via coordination bonding with Pb^(2+).As a result,the regular-structure planar CsPbI_(2.25)Br_(0.75)PSC device delivers a champion power conversion efficiency(PCE)of 17.04%,which surpasses that of the control device(15.44%).Moreover,the PCBDMAM-incorporated PSC device maintains~80%of its initial PCE after 600 h heating at 85°C hot plate in N2 atmosphere,whereas PCE of the control device degrades rapidly to~62%after 460 h heating under identical conditions.Hence,PCBDMAM incorporation benefited dramatic improvement of the thermal stability of PSC device.
基金the National Key Research and Development Program of China (2017YFA0206600)the National Natural Science Foundation of China (51773045, 21572041, 21772030 and 51922032)the Youth Association for Promoting Innovation (CAS) for financial support.
文摘In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,17%power conversion efficiencies(PCEs)have been achieved in the state-of-the-art OSCs[2,3].The remarkable progress in OSCs relies on the continuously emerging new materials and device fabrication technologies,and the understanding on film morphology and device physics[4,5].
基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21572041,21772030 and 51922032)the Youth Association for Promoting Innovation(CAS)for financial support
文摘Nowadays,wide-bandgap(WBG)copolymers attract great attention in the field of organic photovoltaics[1].They are ideal electron-donating partners for low-bandgap small molecule acceptors[2-12].With good energy levels matching,the blend of WBG copolymer donor and small molecule acceptor can harvest most of the sunlight and deliver high power conversion efficiencies(PCEs)in solar cells.PCEs higher than 16%have been achieved[13-15].WBG copolymers especially those with ultra-wide bandgaps(i.e.,optical bandgap(Eg opt)>2.07 eV,absorption onset<600 nm)can find applications in ternary solar cells[16]and tandem solar cells[17].Currently,ultra-WBG copolymer donors are less efficient,generally giving PCEs below 13%[18].Designing highly efficient ultra-WBG copolymers is needed.In this work,we use fluorine-and alkoxyl-substituted benzene(FAB)as the building block to construct ultra-WBG copolymer donors.
基金supported by the National Natural Science Foundation of China (U1401244, 21374025,21372053,21572041,and 51503050)the National Key Research and Development Program of China (2017YFA0206600)+2 种基金the State Key Laboratory of Luminescent Materials and Devices(2016-skllmd-05)the Youth Association for Promoting Innovation(CAS)the U.S.Office of Naval Research(N00014-15-1-2244)for financial support
文摘Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs)over 13% have been realized in single-junction NFOSCs[2].Compared with traditional fullerene acceptors,the greatest advantage of nonfullerene acceptors is their stronger light-harvesting capability in the visible and
基金the National Key Research and Development Program of China (2017YFA0206600)the National Natural Science Foundation of China (51773045, 21572041 and 21772030) for financial support
文摘Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell-efficiency.html.
基金supported by the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)。
文摘Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,18%power conversion efficiency has been achieved in the state-of-the-art organic solar cells.The recent rapid progress in organic solar cells relies on the continuously emerging new materials and device fabrication technologies,and the deep understanding on film morphology,molecular packing and device physics.Donor and acceptor materials are the key materials for organic solar cells since they determine the device performance.The past 25 years have witnessed an odyssey in developing high-performance donors and acceptors.In this review,we focus on those star materials and milestone work,and introduce the molecular structure evolution of key materials.These key materials include homopolymer donors,D-A copolymer donors,A-D-A small molecular donors,fullerene acceptors and nonfullerene acceptors.At last,we outlook the challenges and very important directions in key materials development.
